1. Field of the Invention
The present invention relates to a substrate treating method and a substrate treating apparatus for polishing a peripheral portion of a substrate such as a semiconductor wafer.
2. Description of the Related Art
In recent years, along with finer structures of semiconductor elements and higher integration of semiconductor devices, it has become important to remove surface roughness which is produced at a peripheral portion (bevel portion and edge portion) of a semiconductor wafer (substrate) or a film which attaches to a peripheral portion (bevel portion and edge portion) of a substrate to cause contamination.
As techniques for the above objects, there are conventionally known methods such as a polishing method, an etching method, and a method using a microtorch. Among them, the polishing method is used extensively because its processing time is short and controllability of a treating region is relatively high. According to the polishing method, in general, a substrate is rotated in a circumferential direction, and a polishing member such as a polishing tape is pressed onto a surface of a peripheral portion of the substrate to polish it.
But, the conventional polishing technique is hard to press the polishing member effectively and appropriately onto a large area of the peripheral portion of a semiconductor wafer. Further, since the conventional polishing technique polishes a bevel portion of a semiconductor wafer, an edge portion polishing apparatus is required in addition to the bevel portion polishing apparatus in order to polish a flat surface portion (i.e. edge portion) next to the bevel portion. In such a case, the polishing mechanism and the polishing process become complex, possibly resulting in lower efficiency of polishing, a higher processing cost and a lower yield.